Welding and other protective helmets and head gear are well known in the prior art. These helmets are generally worn on the head of the user and protect his head, face and eyes. They typically include a hard protective shell which covers the users head in some manner and a support strap of some kind that fastens to the protective shell and mounts it to the user's head. For comfort and a secure fit, there is usually provided some kind of adjustment not only in the head gear strap itself but also in the point of attachment between the protective shell and the head gear. However, this point of attachment is generally not seriously considered as a likely place to provide any significant adjustment not only for cost reasons, but also because the head gear strap is itself typically adjustable. In the welding helmet application in particular, this connection point between the shell and the head gear is perhaps more important as a welder will typically "nod" his helmet up and out of the way, or down in protective position, with a sharp sudden movement of his head. With this "nodding" movement, the connection point provides a point of pivot for the protective shell which is independent of any head gear adjustment. Thus, at least for welding helmets, or for any protective helmet for which this "nodding" motion is used, the pivot point at the connection has increased importance. Another aspect to this "nodding" motion is that continuous movement will have a tendency to loosen the pivot point, as the shell can be not insubstantially light and generate a torque as it is "nodded". Additionally, the welding helmet may vary in weight as the user adds, deletes, or changes filters or otherwise modifies his helmet configuration. Thus, a proper "nodding" movement will not be achieved should the weight of the shell be changed. Therefore, it would be desirable to provide a pivot connection that allows the user to readily adjust the frictional engagement between the shell and the head gear to accommodate such changes in weight.
This pivot point connection is also the point where the range of movement for the shell needs to be controlled in order that when "nodded", the shell moves between a desired up position and a desired down position. Obviously, for different users, these end or stopped positions will vary due to their anatomical differences. Furthermore, it is important that these end or stopped positions be somewhat reliably set, and maintained, as a welder could be less than attentive and assume that the shell will move to where he thought it was adjusted and should the shell slip or otherwise not fully move to the proper position, he could find himself welding or at least striking an arc with the helmet not in its full protective position. Injury could occur should the welder be careless in this manner. Therefore, incorporating this mechanical stop into a pivot connection can be important to a safe and idiot proof operation of the helmet.
In the prior art, this connection point was not focussed on and many welding helmets have simple screw fasteners which tighten down on the shell itself, using the simple annular area of a bolt or accompanying washer as the surface against which the frictional forces are developed. These are found to routinely work themselves loose through repeated use. Or, complicated structure has been used in other prior art designs which are an improvement over the simple screw down fasteners, but they can suffer from increased cost and still not provide the additional surface area thought to be needed to develop a workable frictional force that provides safer and more reliable operation.
In order to solve these and other problems in the prior art, the inventor herein has succeeded in designing and developing a pivot connection that is elegantly simple, with a minimum number of parts and hence inexpensive, which provides a greatly increased surface area for developing a significantly greater frictional force and which at the same time is infinitely adjustable by the user with a simple finger sized twist knob. This same elegantly simple design further provides two mechanical stops for a user to adjust the limit of movement of the helmet during the "nodding" motion. One of these mechanical stops is user adjustable with the parts provided to set the end points of the movement, and the other is adjustable by changing out a single piece of the assembly. Together they determine the end points of the "nodding" motion and also provide a mechanical track along which the parts are guided as they move to better control the movement. Essentially, these parts include an outside finger adjust knob with a threaded hole, a conical pivot stop having a conical surface and a pin for insertion in one of a number of matching holes in the helmet interior to fix its angular orientation, the conical pivot stop having a conical surface with a central hole, a strap member for attachment to the head gear with the strap member including a matching conical surface with central hole, and a fastening bolt for insertion through all of the parts and threading into the finger adjust knob. Thus, these few parts provide the pivot connection between the helmet shell and the head gear, a conical surface against which a significantly increased frictional force is developed dependent on the user's tightening of the finger knob, and a mechanical stop which adjustably fixes the end points of motion and which tracks the parts to better control their movement and ensure that they move smoothly and accurately. The parts may be made of any convenient material such as high impact plastic or other materials which will hold up under the conditions of use. These parts can be made with high speed production equipment and can be assembled readily without specific adjustment required at the factory. The parts are thus low cost, and while some Limited assembly is required, the invention provides increased functionality at Lower cost than those pivot connections of the prior art.